1. Field of Invention
This invention relates to moisture-proof packaging containers. In particular this invention includes a moisture-proof packaging container containing a humidity indicator system which visually discloses the humidity of the air within the container.
2. Prior Art
Plastic semiconductor devices are susceptible to moisture due to the permeable nature of their plastic components. It is well known that integrated circuits which are contaminated by high levels of moisture may not be useful. Mechanical failure of such contaminated integrated circuits often leads to the subsequent electrical failure of the device which contains the integrated circuit due to thermal and mechanical stresses. Accordingly, exposure of integrated circuits to moisture should be limited.
This concern about limiting the exposure of integrated circuits to moisture has been addressed in the design of shipping packaging for integrated circuits. Currently the preferred method to form a packaging system for integrated circuits includes baking the integrated circuit devices until dry, placing them into a water and humidity proof packaging bag which contains desiccant packets and a humidity indicator card, sealing the bag immediately, and then shipping the device to the customer in these packaging bags. U.S. Pat. No. 4,971,196, 5,095,626, 5,293,996 and 5,295,297 address this problem by disclosing specialized types of packaging for semiconductor products. Each of the packaging containers disclosed by these patents incorporates a moisture indicator device into the packaging material which device is secured to the inside surface of the packaging. See specifically FIGS. 7 and 10 of these patents.
U.S. Pat. No. 5,293,996 in particular discloses a package container for the shipment of integrated circuits containing an observation window. The container is divided into three sections, wherein one of those sections contains a compartment (11) housing a humidity indicator device (16). The humidity indicator device (16) is preferably a humidity indicator card, manufactured by Humidial Corporation. As best understood the card is merely placed within the compartment. The composition of the packaging material of the compartment containing the humidity indicator card is a transparent plastic, thus permitting the moisture indicator card to be viewed from outside of the packaging container.
U.S. Pat. No. 5,318,181 discloses compartmentalized humidity sensing indicators. These humidity sensing indicators are produced on a tape reel and are secured to the inside surface of a continuous strip of humidity indicators.
U.S. Pat. No. 2,446,361 discloses a humidity indicating moisture adsorbent product secured to packaged goods. The product comprises a container (A) onto which is secured a receptacle (B). Contained within the receptacle (B) is a desiccant (C). The receptacle (B) is transparent, may be formed from plastic materials and is screwed into a threaded mounting apparatus which is also secured to the container. It is comprised of a cylindrical wall (16), closed top (17) and a perforated bottom (18). The receptacle (B) is secured in place to the package by a collar (20) and a locking ring (22) containing threads (24, 28). The receptacle (B) is screwed in place using two different designs as disclosed in FIGS. 2 and 3 of the patent. See also U.S. Pat. No. 5,238,648 which discloses a view port in the packaging through which can be viewed an oxygen indicator device.
Current packaging products which are used to ship integrated circuits still exhibit deficiencies, including limitations on the composition of the packaging material. Conventionally, the packaging material used for shipping integrated circuits is opaque, thus preventing easy inspection of the humidity indicator card contained within the packaging unless the packaging material is breached. In certain new products, the composition of the surface material of the packaging must be different from the composition of the remaining portion of the packaging that is adjacent to the humidity indicator so that the humidity indicator card can be viewed from outside of the packaging. In addition, the method for attachment of the humidity indicator device to the inside surface of the packaging material is often not practical.
Accordingly, it is an object of this invention to produce a packaging container which incorporates a humidity indicator device.
It is a further object of this invention to disclose a packaging container which incorporates a humidity indicator device, wherein the humidity indicator device is secured to the packaging material by a securing system.
It is a still further object of this invention to disclose a packaging container which incorporates a humidity indicator device which is easy to produce and accurately discloses the level of the humidity within the packaging container.
It is a still further object of this invention to disclose a packaging container which incorporates a humidity indicator device, comprising a humidity indicator element, with or without a humidity comparison element, and a securing system for securing the humidity indicator element with or without a humidity comparison element together to the packaging container.
These and other objects and features of the present invention will become apparent to those skilled in the art from a consideration of the following detailed description, drawings and claims. The description along with the accompanying drawings provides a selected example of the construction of the device to illustrate the invention.